题目内容
在横线上填入合适的关系代词。
The old woman has two sons, one of ________ is a teacher．
The last place ________ we visited was the Great Wall．
________ we know now, bats come out only at night．
This is Mr Smith, ________ I think has something interesting to tell us．
The clever boy made a hole in the wall, through ________ he could see what was going on inside the house．
